ABSTRACT
Definition The strict definition for hurricane, typhoon, etc. is that it is a large-scale (some hundreds of kilometres across) low pressure system forming over the tropical oceans. It has a core which is warmer than the surrounding atmo sphere. Additionally, it has an 'eye' in the centre and spiral rain bands running in towards this centre. The really important criterion is that the maximum sustained surface winds (see below for an explanation) must equal or exceed force 12 on the Beaufort scale (i.e. hurricane force) which equates to some 33 metres per second (74 miles per hour).
